Organic light-emitting device having low work function metal halide compound in hole injection layer

ABSTRACT

Provided is an organic light-emitting device including a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, the organic layer including a low work function metal compound.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2014-0122935, filed on Sep. 16, 2014,in the Korean Intellectual Property Office, and entitled: “OrganicLight-Emitting Device,” is incorporated by reference herein in itsentirety.

BACKGROUND

1. Field

One or more exemplary embodiments relate to an organic light-emittingdevice.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that may havewide viewing angles, high contrast ratios, short response times, andexcellent brightness, driving voltage, and response speedcharacteristics, and may produce full-color images.

SUMMARY

Embodiments may be realized by providing an organic light-emittingdevice, including a first electrode; a second electrode facing the firstelectrode; and an organic layer between the first electrode and thesecond electrode and including an emission layer, the organic layerincluding a low work function metal compound.

The low work function metal compound may have a work function in a rangeof more than 0 eV to about 3 eV.

The low work function metal compound may include a halide of an alkalimetal.

The low work function metal compound may include a halide of an alkalineearth metal.

The low work function metal compound may include a halide of alanthanide metal.

The low work function metal compound may include a halide of Li, Na, K,Rb, Cs, Be, Mg, Ca, Sr, Ba, Yb, or Sm.

The low work function metal compound may include LiF, NaF, KF, RbF, CsF,BeF₂, MgF₂, CaF₂, SrF₂, BaF₂, YbF, YbF₂, YbF₃, or SmF₃.

The low work function metal compound may include LiCl, NaCl, KCl, RbCl,CsCl, BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, YbCl, YbCl₂, YbCl₃, or SmCl₃.

The low work function metal compound may include LiBr, NaBr, KBr, RbBr,CsBr, BeBr₂, MgBr₂, CaBr₂, SrBr₂, BaBr₂, YbBr, YbBr₂, YbBr₃, or SmBr₃.

The low work function metal compound may include LiI, NaI, KI, RbI, CsI,BeI₂, MgI₂, CaI₂, SrI₂, BaI₂, YbI, YbI₂, YbI₃, or SmI₃.

The first electrode may be an anode, the second electrode may be acathode, and the organic layer may include a layer including the lowwork function metal compound, a hole transport region between the firstelectrode and the emission layer, and including one or more of a holeinjection layer, a hole transport layer, or an electron blocking layer,and an electron transport region between the emission layer and thesecond electrode, and including one or more of a hole blocking layer, anelectron transport layer, or an electron injection layer.

The layer including the low work function metal compound may be in thehole transport region.

The layer including the low work function metal compound may consist ofa low work function metal compound.

The thickness of the layer including the low work function metalcompound may be in a range of about 1 Å to about 30 Å.

The layer including the low work function metal compound may consist ofa low work function metal compound and a hole injection material.

The thickness of the layer including the low work function metalcompound may be in a range of about 1 Å to about 100 Å.

The layer including the low work function metal compound may contact ananode.

The layer including the low work function metal compound may consist ofa low work function metal compound.

The layer including the low work function metal compound may consist ofa low work function metal compound and a hole injection material.

Embodiments may be realized by providing a flat display apparatus,including the presently disclosed organic light-emitting device. Thefirst electrode of the organic light-emitting device may be electricallyconnected to a source or drain electrode of a thin film transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates a schematic view of an organic light-emitting deviceaccording to an embodiment;

FIG. 2 illustrates a schematic cross-sectional view of an organiclight-emitting device according to an embodiment;

FIG. 3 illustrates a schematic cross-sectional view of an organiclight-emitting device according to an embodiment; and

FIG. 4 illustrates a graph of an efficiency of each of the devices ofExample 1 and Comparative Example 1.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

An organic light-emitting device according to an aspect of someembodiments includes:

a first electrode;

a second electrode facing the first electrode; and

an organic layer disposed between the first electrode and the secondelectrode and including an emission layer,

wherein the organic layer includes a layer including a low work functionmetal compound.

A hole injection layer including CuI having a high work function may beused to provide a device that may lower an energy barrier of an anodeand the hole injection layer.

A hole injection barrier may be lowered when an organic light-emittingdevice includes a layer including a low work function metal compound.However, in a case in which the low work function metal compounddissociates, the low work function metal compound may rather increase anenergy barrier. In this regard, a metal compound used herein may have astrong binding force.

In some embodiments, the low work function metal compound may have awork function in a range of more than 0 eV to about 3 eV.

In some embodiments, the low work function metal compound may include ahalide of an alkali metal, a halide of an alkaline earth metal, or ahalide of a lanthanide metal.

In some embodiments, the low work function metal compound may include ahalide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Yb, or Sm.

In some embodiments, the low work function metal compound may includeLiCl, NaCl, KCl, RbCl, CsCl, BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, YbCl,YbCl₂, YbCl₃, SmCl₃, LiBr, NaBr, KBr, RbBr, CsBr, BeBr₂, MgBr₂, CaBr₂,SrBr₂, BaBr₂, YbBr, YbBr₂, YbBr₃, SmBr₃, LiI, NaI, KI, RbI, CsI, BeI₂,MgI₂, CaI₂, SrI₂, BaI₂, YbI, YbI₂, YbI₃, or SmI₃. For example, the lowwork function metal compound may include LiI, NaI, KI, RbI, or CsI.

In some embodiments, in the organic light-emitting device, the firstelectrode may be an anode, the second electrode may be a cathode, andthe organic layer may include:

i) a layer including a low work function metal compound,

ii) a hole transport region disposed between the first electrode and theemission layer, and including at least one selected from a holeinjection layer, a hole transport layer, and an electron blocking layer,and

iii) an electron transport region disposed between the emission layerand the second electrode, and including at least one selected from ahole blocking layer, an electron transport layer, and an electroninjection layer.

In some embodiments, the layer including the low work function metalcompound may be disposed in the hole transport region.

In some embodiments, the layer including the low work function metalcompound may be formed of a low work function metal compound. The layerincluding the low work function metal compound may include only a lowwork function metal compound.

In some embodiments, the thickness of the layer that includes only a lowwork function metal compound may be in a range of about 1 Å to about 30Å.

The organic light-emitting device may have a maximum efficiency when thethickness of the layer is maintained within the aforementioned range.

In some embodiments, the layer including a low work function metalcompound may be formed of a low work function metal compound and a holeinjection material. The thickness of the layer formed of a low workfunction metal compound and a hole injection material may be in a rangeof about 1 Å to about 100 Å.

The organic light-emitting device may have a maximum efficiency when thethickness of the layer is maintained within the aforementioned range.

The volume percent ratio of low work function metal compound:holeinjection material may be in a range of about 1:60 to about 60:1. Forexample, the volume percent ratio may be in a range of about 1:50 toabout 50:1. The organic light-emitting device may have a maximumefficiency when the volume percent ratio thereof is maintained withinthe aforementioned range. For example, the low work function metalcompound and the hole injection material might be codeposited in volumeunit.

A low work function metal compound may be co-deposited on the holetransport layer, the low work function metal compound may take electronsfrom a hole transport material, and p-doping may occur.

In some embodiments, the layer including a low work function metalcompound may contact an anode. The layer including the low work functionmetal compound may be formed of only a low work function metal compound,or of a low work function metal compound and a hole injection material.

The expression “(an organic layer) includes at least one grouprepresented by Formula x” used herein may include identical grouprepresented by Formula x and two or more different group represented byFormula x.

The term “organic layer” used herein refers to a single layer and/or aplurality of layers disposed between the first electrode and the secondelectrode of an organic light-emitting device. Materials included in the“organic layer” are not limited to organic materials.

FIG. 1 illustrates a schematic view of an organic light-emitting device10 according to an embodiment. The organic light-emitting device 10 mayinclude a first electrode 110, an organic layer 150, and a secondelectrode 190.

Hereinafter, the structure of an organic light-emitting device accordingto an embodiment and a method of manufacturing an organic light-emittingdevice according to an embodiment will be described in connection withFIG. 1.

In FIG. 1, a substrate may be additionally disposed under the firstelectrode 110 or above the second electrode 190. The substrate may be aglass substrate or transparent plastic substrate, each with excellentmechanical strength, thermal stability, transparency, surfacesmoothness, ease of handling, and water repellency.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode on the substrate. When thefirst electrode 110 is an anode, the material for the first electrode110 may be selected from materials having a high work function to makeholes be easily injected. The first electrode 110 may be a reflectiveelectrode, a semi-transmissive electrode or a transmissive electrode.The material for the first electrode 110 may be a transparent and highlyconductive material, and examples of such a material are indium tinoxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), and zinc oxide(ZnO). When the first electrode 110 is a semi-transmissive electrode ora reflective electrode, as a material for forming the first electrode,at least one selected from magnesium (Mg), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), andmagnesium-silver (Mg—Ag) may be used.

The first electrode 110 may have a single-layer structure, or amulti-layer structure including two or more layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO.

The organic layer 150 may be disposed on the first electrode 110. Theorganic layer 150 may include an emission layer. A layer including a lowwork function metal compound may contact the first electrode 110.

The organic layer 150 may further include a hole transport regiondisposed between the first electrode and the emission layer, and anelectron transport region disposed between the emission layer and thesecond electrode.

The hole transport region may include, for example, a layer including alow work function metal compound, and at least one selected from a holetransport layer (HTL), a hole injection layer (HIL), and a buffer, andthe electron transport region may include, for example, at least oneselected from a hole blocking layer (HBL), an electron transport layer(ETL), and an electron injection layer (EIL).

According to an embodiment, the hole injection layer may be a layerformed of a low work function metal compound; or a layer formed of a lowwork function metal compound and a hole injection material.

The hole transport region may have a single-layered structure formed ofa single material, a single-layered structure formed of a plurality ofdifferent materials, or a multi-layered structure having a plurality oflayers formed of a plurality of different materials.

For example, the hole transport region may have a single-layeredstructure formed of a plurality of different materials, or may have astructure of a layer formed of only a low work function metalcompound/hole transport layer, a layer formed of a low work functionmetal compound and a hole injection material/hole transport layer, alayer formed of a low work function metal compound and a hole injectionmaterial/hole transport layer/buffer layer, a hole injectionlayer/buffer layer, a hole transport layer/buffer layer, or a holeinjection layer/hole transport layer/electron blocking layer. In eachstructure of the hole transport region, constituting layers may be, forexample, sequentially stacked from the first electrode 110 in the statedorder.

When the hole transport region includes a hole injection layer, the holeinjection layer may be formed on the first electrode 110 using variousmethods, such as vacuum deposition, spin coating casting, aLangmuir-Blodgett (LB) method, ink jet printing, laser-printing, orlaser-induced thermal imaging.

When a hole injection layer is formed by vacuum deposition, for example,the vacuum deposition may be performed at a temperature of a depositiontemperature of about 100 to about 500° C., at a vacuum degree of about10⁻⁸ to about 10⁻³ torr, and at a deposition rate of about 0.01 to about100 Å/sec in consideration of a compound for a hole injection layer tobe deposited, and the structure of a hole injection layer to be formed.

When a hole injection layer is formed by spin coating, the spin coatingmay be performed at a coating rate of about 2000 rpm to about 5000 rpm,and at a temperature of about 80° C. to 200° C. in consideration of acompound for a hole injection layer to be deposited, and the structureof a hole injection layer to be formed.

When the hole transport region includes a hole transport layer, the holetransport layer may be formed on the first electrode 110 or the holeinjection layer using various methods, such as vacuum deposition, spincoating, casting, a LB method, ink jet printing, laser-printing, orlaser-induced thermal imaging. When the hole transport layer is formedby vacuum deposition or spin coating, deposition and coating conditionsfor the hole transport layer may be the same as the deposition andcoating conditions for the hole injection layer.

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1000 Å. When thehole transport region includes both a hole injection layer and a holetransport layer, a thickness of the hole injection layer may be in arange of about 100 Å to about 10000 Å, for example, about 100 Å to about1000 Å, and a thickness of the hole transport layer may be in a range ofabout 50 Å to about 2000 Å, for example about 100 Å to about 1500 Å.When the thicknesses of the hole transport region, the hole injectionlayer, and the hole transport layer are within these ranges,satisfactory hole transporting characteristics may be provided without asubstantial increase in driving voltage.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be one of, for example, a quinone derivative, a metaloxide, and a cyano group-containing compound. Examples of the p-dopantinclude a quinone derivative, such as, for example,tetracyanoquinonedimethane (TCNQ) or2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); ametal oxide, such as for example, a tungsten oxide or a molybdenumoxide, and Compound HT-D1 illustrated below.

The hole transport region may further include a buffer layer, inaddition to an electron blocking layer, a hole injection layer, and ahole transport layer. The buffer layer may compensate for an opticalresonance distance according to a wavelength of light emitted from theemission layer, and light-emission efficiency of a formed organiclight-emitting device may be improved. For use as a material included inthe buffer layer, materials that are included in the hole transportregion may be used. The electron blocking layer may prevent injection ofelectrons from the electron transport region.

An emission layer is formed on the first electrode 110 or the holetransport region using various methods, such as vacuum deposition, spincoating, casting, a LB method, ink-jet printing, laser-printing, orlaser-induced thermal imaging. When an emission layer is formed byvacuum deposition or spin coating, deposition and coating conditions forthe emission may be the same as those for the hole injection layer.

When the organic light-emitting device 10 is a full color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, or a blue emission layer,according to a sub pixel. In some embodiments, the emission layer mayhave a stacked structure of a red emission layer, a green emissionlayer, and a blue emission layer, or may include a red-light emissionmaterial, a green-light emission material, and a blue-light emissionmaterial, which are mixed with each other in a single layer, to emitwhite light.

The emission layer may include a host and a dopant.

The host may include at least one selected from, for example, TPBi,TBADN, AND (also referred to as “DNA”), CBP, CDBP and TCP below:

According to an embodiment, the host may include a group represented byFormula 301 below:Ar₃₀₁-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb2)  <Formula 301>

wherein in Formula 301,

Ar₃₀₁ may be selected from

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene; and

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected from adeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃) (Q₃₀₁ to Q₃₀₃ may be each independently selectedfrom a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₆-C₆₀aryl group, and a C₂-C₆₀ heteroaryl group);

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₂-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₂-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₂-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group;

R₃₀₁ may be selected from

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, and a triazinyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazol group, and a triazinyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, and a triazinyl group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, aquinolinyl group, an isoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a carbazolyl group, and a triazinyl group; and

xb1 may be selected from 0, 1, 2, and 3;

xb2 may be selected from 1, 2, 3, and 4.

For example, in Formula 301

L301 may be selected from

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-fluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a pyrenylene group, and a chrysenylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-fluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a pyrenylene group, and a chrysenylene group, each substitutedwith at least one selected from a deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid or a saltthereof, a sulfonic acid or a salt thereof, a phosphoric acid or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, and a chrysenyl group;

R₃₀₁ may be selected from

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, and a chrysenyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, and a chrysenyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, and a chrysenyl group,each substituted with at least one selected from a deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoricacid or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, and a chrysenyl group.

For example, the host may include a group represented by Formula 301Abelow:

Substituents of Formula 301A may be understood by correspondingdescriptions provided herein.

The group represented by Formula 301 may include, for example, at leastone selected from Compounds H1 to H42:

The dopant may be at least one selected from a fluorescent dopant and aphosphorescent dopant.

The phosphorescent dopant may include an organometallic complexrepresented by Formula 401 below:

wherein in Formula 401,

M may be selected from iridium (Ir), platinum (Pt), osmium (Os),titanium (Ti), zirconium (Zr), hafnium (Hf), euroform (Eu), terbium(Tb), and tolium (TM);

X₄₀₁ to X₄₀₄ may be each independently nitrogen or carbon;

A₄₀₁ and A₄₀₂ rings may be each independently selected from asubstituted or unsubstituted benzene group, a substituted orunsubstituted naphthalene group, a substituted or unsubstitutedfluorenene group, a substituted or unsubstituted spiro-fluorenene group,a substituted or unsubstituted indene group, a substituted orunsubstituted pyrrole group, a substituted or unsubstituted thiophenegroup, a substituted or unsubstituted furan group, a substituted orunsubstituted imidazole group, a substituted or unsubstituted pyrazolegroup, a substituted or unsubstituted thiazole group, a substituted orunsubstituted isothiazole group, a substituted or unsubstituted oxazolegroup, a substituted or unsubstituted isoxazole group, a substituted orunsubstituted pyridine group, a substituted or unsubstituted pyrazinegroup, a substituted or unsubstituted pyrimidine group, a substituted orunsubstituted pyridazine group, a substituted or unsubstituted quinolinegroup, a substituted or unsubstituted isoquinoline group, a substitutedor unsubstituted benzoquinoline group, a substituted or unsubstitutedquinoxaline group, a substituted or unsubstituted quinazoline group, asubstituted or unsubstituted carbazol group, a substituted orunsubstituted benzoimidazole group, a substituted or unsubstitutedbenzofuran group, a substituted or unsubstituted benzothiophene group, asubstituted or unsubstituted isobenzothiophene group, a substituted orunsubstituted benzooxazole group, a substituted or unsubstitutedisobenzooxazole group, a substituted or unsubstituted triazole group, asubstituted or unsubstituted oxadiazole group, a substituted orunsubstituted triazine group, a substituted or unsubstituteddibenzofuran group, and a substituted or unsubstituted dibenzothiophenegroup; and

at least one substituent of the substituted benzene group, substitutednaphthalene group, substituted fluorenene group, substitutedspiro-fluorenene group, substituted indene group, substituted pyrrolegroup, substituted thiophene group, substituted furan group, substitutedimidazole group, substituted pyrazole group, substituted thiazole group,substituted isothiazole group, substituted oxazole group, substitutedisoxazole group, substituted pyridine group, substituted pyrazine group,substituted pyrimidine group, substituted pyridazine group, substitutedquinoline group, substituted isoquinoline group, substitutedbenzoquinoline group, substituted quinoxaline group, substitutedquinazoline group, substituted carbazol group, substitutedbenzoimidazole group, substituted benzofuran group, substitutedbenzothiophene group, substituted isobenzothiophene group, substitutedbenzooxazole group, substituted isobenzooxazole group, substitutedtriazole group, substituted oxadiazole group, substituted triazinegroup, substituted dibenzofuran group, and substituted dibenzothiophenegroup may be selected from

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₄₀₁)(Q₄₀₂), —Si(Q₄₀₃)(Q₄₀₄)(Q₄₀₅),and —B(Q₄₀₆)(Q₄₀₇);

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, and a non-aromatic condensed polycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₄₁₁)(Q₄₁₂), —Si(Q₄₁₃)(Q₄₁₄)(Q₄₁₅)and —B(Q₄₁₆)(Q₄₁₇); and

—N(Q₄₂₁)(Q₄₂₂), —Si(Q₄₂₃)(Q₄₂₄)(Q₄₂₅), and —B(Q₄₂₆)(Q₄₂₇),

L₄₀₁ is an organic ligand;

xc1 is 1, 2, or 3; and

xc2 is 0, 1, 2, or 3.

L₄₀₁ may be a monovalent, divalent, or trivalent organic ligand. Forexample, L₄₀₁ may be selected from a halogen ligand (for example, Cl orF), a diketone ligand (for example, acetylacetonate,1,3-diphenyl-1,3-propandionate, 2,2,6,6-tetramethyl-3,5-heptandionate,or hexafluoroacetonate), a carboxylic acid ligand (for example,picolinate, dimethyl-3-pyrazolecarboxylate, or benzoate), a carbonmonooxide ligand, an isonitrile ligand, a cyano ligand, and aphosphorous ligand (for example, phosphine, and phosphite).

When A₄₀₁ in Formula 401 has two or more substituents, the substituentsof A₄₀₁ may bind to each other to form a saturated or unsaturated ring.

When A₄₀₁ in Formula 402 has two or more substituents, the substituentsof A₄₀₂ may bind to each other to form a saturated or unsaturated ring.

When xc1 in Formula 401 is two or more, a plurality of ligands

in Formula 401 may be identical or different. When xc1 in Formula 401 istwo or more, A₄₀₁ and A₄₀₂ may be respectively directly connected toA₄₀₁ and A₄₀₂ of other neighboring ligands with or without a linker (forexample, a C₁-C₅ alkylene, or —N(R′)— (wherein R′ may be a C₁-C₁₀ alkylgroup or a C₆-C₂₀ aryl group) or —C(═O)—) therebetween.

The phosphorescent dopant may include, for example, at least oneselected from Compounds PD1 to PD74 below:

According to an embodiment, the phosphorescent dopant may include PtOEP:

The fluorescent dopant may include at least one selected from DPAVBi,BDAVBi, TBPe, DCM, DCJTB, Coumarin 6, and C545T.

According to an embodiment, the fluorescent dopant may include a grouprepresented by Formula 501 below:

wherein in Formula 501,

Ar₅₀₁ may be selected from

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene; and

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected from adeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₅₀₁)(Q₅₀₂)(Q₅₀₃) (Q₅₀₁ to Q₅₀₃ may be each independently selectedfrom a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₆-C₆₀aryl group, and a C₂-C₆₀ heteroaryl group);

descriptions of L₅₀₁ to L₅₀₃ may be the same as the description providedherein in connection with L₃₀₁;

R₅₀₁ and R₅₀₂ may be each independently selected from

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, a triazinyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, a triazinyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from a deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid or a saltthereof, a sulfonic acid or a salt thereof, a phosphoric acid or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, aquinolinyl group, an isoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a carbazolyl group, a triazinyl group, adibenzofuranyl group, and a dibenzothiophenyl group;

xd1 to xd3 may be each independently selected from 0, 1, 2, and 3; and

xb4 may be selected from 1, 2, 3, and 4.

The fluorescent host may include at least one selected from CompoundsFD1 to FD8.

An amount of the dopant in the emission layer may be, for example, in arange of about 0.01 to about 15 parts by weight based on 100 parts byweight of the host.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. Maintaining thethickness of the emission layer within this range may help provideexcellent light-emission characteristics without a substantial increasein driving voltage.

Then, an electron transport region may be disposed on the emissionlayer.

The electron transport region may include, for example, at least oneselected from a hole blocking layer, an electron transport layer (ETL),and an electron injection layer.

For example, the electron transport region may have a structure ofelectron transport layer/electron injection layer or a structure of holeblocking layer/electron transport layer/electron injection layer,wherein layers of each structure are, for example, sequentially stackedfrom the emission layer in the stated order.

According to an embodiment, the organic layer 150 of the organiclight-emitting device may include an electron transport region disposedbetween the emission layer and the second electrode 190.

The electron transport region may include a hole blocking layer. Thehole blocking layer may be formed, when the emission layer includes aphosphorescent dopant, to prevent diffusion of excitons or holes into anelectron transport layer.

When the electron transport region includes a hole blocking layer, thehole blocking layer may be formed on the emission layer using variousmethods, such as vacuum deposition, spin coating casting, aLangmuir-Blodgett (LB) method, ink-jet printing, laser-printing, orlaser-induced thermal imaging. When the hole blocking layer is formed byvacuum deposition or spin coating, deposition and coating conditions forthe hole blocking layer may be determined by referring to the depositionand coating conditions for the hole injection layer.

The hole blocking layer may include, for example, at least one selectedfrom BCP and Bphen.

A thickness of the hole blocking layer may be in a range of about 20 Åto about 1,000 Å, for example, about 30 Å to about 300 Å. Maintainingthe thickness of the hole blocking layer within these ranges may helpprovide the hole blocking layer excellent hole blocking characteristicswithout a substantial increase in driving voltage.

The electron transport region may include an electron transport layer.The electron transport layer may be formed on the emission layer or thehole blocking layer using various methods, such as vacuum deposition,spin coating casting, a LB method, ink-jet printing, laser-printing, orlaser-induced thermal imaging. When an electron transport layer isformed by vacuum deposition or spin coating, deposition and coatingconditions for the electron transport layer may be the same as thedeposition and coating conditions for the hole injection layer.

According to an embodiment, the organic layer 150 of the organiclight-emitting device includes an electron transport region disposedbetween the emission layer and the second electrode 190, and theelectron transport region may include an electron transport layer. Theelectron transport layer may include a plurality of layers. For example,the electron transport layer may include a first electron transportlayer and a second electron transport layer.

The electron transport layer may further include, in addition to anorganometallic group, at least one selected from BCP, Bphen, Alq₃, Balq,TAZ, and NTAZ.

According to an embodiment, the electron transport layer may include atleast one group selected from a group represented by Formula 601 and agroup represented by Formula 602 illustrated below:Ar₆₀₁-[(L₆₀₁)_(xe1)-E₆₀₁]_(xe2)  <Formula 601>

wherein in Formula 601,

Ar₆₀₁ may be selected from

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene;

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected from adeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₃-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₃-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃) (Q₃₀₁ to Q₃₀₃ may be each independently selectedfrom a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₆-C₆₀aryl group, and a C₂-C₆₀ heteroaryl group);

descriptions of L₆₀₁ may be the same as the description provided hereinin connection with L₃₀₁;

E₆₀₁ may be selected from

a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group; and

a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, each substitutedwith at least one selected from a deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid or a saltthereof, a sulfonic acid or a salt thereof, a phosphoric acid or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentylgroup, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a pentalenyl group, an indenylgroup, a naphthyl group, an azulenyl group, a heptalenyl group, anindacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group,a phenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a naphthacenyl group, a picenyl group, a perylenyl group, apentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenylgroup, a coronenyl group, an ovalenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, an imidazolyl group, a pyrazolylgroup, a thiazolyl group, an isothiazolyl group, an oxazolyl group, anisooxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a furinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzooxazolyl group, an isobenzooxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a thiadiazolyl group, animidazopyridinyl group, and an imidazopyrimidinyl group;

xe1 may be selected from 0, 1, 2, and 3; and

xe2 may be selected from 1, 2, 3, and 4.

In Formula 602,

X₆₁₁ may be N or C-(L₆₁₁)_(xe611)-R₆₁₁, X₆₁₂ may be N orC-(L₆₁₂)_(xe612)-R₆₁₂, X₆₁₃ may be N or C-(L₆₁₃)_(xe613)-R₆₁₃, and atleast one selected from X₆₁₁ to X₆₁₃ may be N;

descriptions of L₆₁₁ to L₆₁₆ may be the same as the description providedherein in connection with L₃₀₁;

R₆₁₁ and R₆₁₆ may be each independently selected from

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, and a triazinyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenylgroup, an anthracenyl group, a pyrenyl group, a chrysenyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, a carbazolyl group, and a triazinyl group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, aquinolinyl group, an isoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a carbazolyl group, and a triazinyl group; and

xe611 to xe616 may be each independently selected from 0, 1, 2, and 3.

The group represented by Formula 601 and the group represented byFormula 602 may each be selected from Compounds ET1 to ET15 illustratedbelow.

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å.Maintaining the thickness of the electron transport layer within therange described above may help provide the electron transport layersatisfactory electron transport characteristics without a substantialincrease in driving voltage.

The electron transport layer may further include, in addition to thematerials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium quinolate, LiQ) orET-D2.

The electron transport region may include an electron injection layerthat allows electrons to be easily provided from the second electrode190.

The electron injection layer may be formed on the electron transportlayer using various methods, such as vacuum deposition, spin coatingcasting, a LB method, ink-jet printing, laser-printing, or laser-inducedthermal imaging. When an electron injection layer is formed by vacuumdeposition or spin coating, deposition and coating conditions for theelectron injection layer may be the same as those for the hole injectionlayer.

The electron injection layer may include at least one selected from,LiF, NaCl, CsF, Li₂O, BaO, and LiQ.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. Maintaining thethickness of the electron injection layer within the range describedabove may help provide the electron injection layer satisfactoryelectron injection characteristics without a substantial increase indriving voltage.

The second electrode 190 may be disposed on the organic layer 150 havingsuch a structure. The second electrode 190 may be a cathode which is anelectron injection electrode, and a material for the second electrode190 may be metal, an alloy, an electrically conductive compound, and amixture thereof, each having a low work function. Detailed examples ofthe second electrode 190 are lithium (Li), magnesium (Mg), aluminum(Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),or magnesium-silver (Mg—Ag). According to an embodiment, the materialfor forming the second electrode 190 may be ITO or IZO. The secondelectrode 190 may be a reflective electrode, a semi-transmissiveelectrode, or a transmissive electrode.

In addition, when an organic light-emitting device according to anembodiment includes an organic layer as described above, the organiclayer may be formed using a deposition method or a wet method in which acompound according to an embodiment prepared in the solution form isused for coating.

An organic light-emitting device according to an embodiment may be usedin various flat panel display apparatuses, such as a passive matrixorganic light-emitting display apparatus or an active matrix organiclight-emitting display apparatus. In particular, when the organiclight-emitting device is included in an active matrix organiclight-emitting display apparatus, a first electrode disposed on asubstrate acts as a pixel and may be electrically connected to a sourceor drain electrode of a thin film transistor. In addition, the organiclight-emitting device may be included in a flat panel display apparatusthat emits light in opposite directions.

FIG. 2 illustrates a schematic cross-sectional view of an organiclight-emitting device according to an embodiment. Referring to FIG. 2, afirst electrode may contact a layer formed of only a low work functionmetal compound, and the layer formed of only a low work function metalcompound may contact a hole transport layer.

Examples of low work function metal compounds are described above. A lowwork function metal compound may lower a hole injection barrier due to adipole moment thereof. However, in a case in which the metal compound isdissociated, a low work function metal compound may increase an energybarrier. In this regard, the low work function metal compound having astrong binding force is required.

FIG. 3 illustrates a schematic cross-sectional view of an organiclight-emitting device according to an embodiment. Referring to FIG. 3, afirst electrode may contact a layer formed of a low work function metalcompound and a hole injection material, and the layer formed of a lowwork function metal compound and a hole injection material may contact ahole transport layer.

Examples of low work function metal compounds are described above. Thelayer is formed of a low work function metal compound and a holeinjection material, the metal compound of the layer may take electronsfrom a hole injection material, and have a p-doping characteristic.

Heretofore, the organic light-emitting device was described byreferring, for example, to FIGS. 1 to 3.

Hereinafter, definitions of substituents used herein will be presented(the number of carbon numbers used to restrict a substituent is notlimited, and does not limit properties of the substituent, and unlessdefined otherwise, the definition of the substituent is consistent witha general definition thereof).

A C₁-C₆₀ alkyl group used herein refers to a linear or branchedaliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, anddetailed examples thereof are a methyl group, an ethyl group, a propylgroup, an isobutyl group, a sec-butyl group, a ter-butyl group, a pentylgroup, an iso-amyl group, and a hexyl group. A C₁-C₆₀ alkylene groupused herein refers to a divalent group having the same structure as theC₁-C₆₀ alkyl group.

A C₁-C₆₀ alkoxy group used herein refers to a monovalent grouprepresented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), anddetailed examples thereof are a methoxy group, an ethoxy group, and anisopropyloxy group.

A C₂-C₆₀ alkenyl group used herein refers to a hydrocarbon group havingat least one carbon double bond in the middle or terminal of the C₂-C₆₀alkyl group, and detailed examples thereof are an ethenyl group, aprophenyl group, and a butenyl group. A C₂-C₆₀ alkenylene group usedherein refers to a divalent group having the same structure as theC₂-C₆₀ alkenyl group.

A C₂-C₆₀ alkynyl group used herein refers to a hydrocarbon group havingone carbon triple bond in the middle or terminal of the C₂-C₆₀ alkylgroup, and detailed examples thereof are an ethynyl group, and apropynyl group. A C₂-C₆₀ alkynylene group used herein refers to adivalent group having the same structure as the C₂-C₆₀ alkynyl group.

A C₃-C₁₀ cycloalkyl group used herein refers to a monovalent hydrocarbonmonocyclic group having 3 to 10 carbon atoms, and detailed examplesthereof are a cyclopropyl group, a cyclobutyl group, a cyclopentylgroup, a cyclohexyl group, and a cycloheptyl group. A C₃-C₁₀cycloalkylene group used herein refers to a divalent group having thesame structure as the C₃-C₁₀ cycloalkyl group.

A C₂-C₁₀ heterocycloalkyl group used herein refers to a monovalentmonocyclic group having at least one hetero atom selected from N, O, P,and S as a ring-forming atom and 2 to 10 carbon atoms, and detailedexamples thereof are a tetrahydrofuranyl group, and atetrahydrothiophenyl group. A C₂-C₁₀ heterocycloalkylene group usedherein refers to a divalent group having the same structure as theC₂-C₁₀ heterocycloalkyl group.

A C₃-C₁₀ cycloalkenyl group used herein refers to a monovalentmonocyclic group that has 3 to 10 carbon atoms and at least one doublebond in the ring thereof and does not have aromacity, and detailedexamples thereof are a cyclopentenyl group, a cyclohexenyl group, and acycloheptenyl group. A C₃-C₁₀ cycloalkenylene group used herein refersto a divalent group having the same structure as the C₃-C₁₀ cycloalkenylgroup.

A C₂-C₁₀ heterocycloalkenyl group used herein refers to a monovalentmonocyclic group that has at least one hetero atom selected from N, O,P, and S as a ring-forming atom, 2 to 10 carbon atoms, and at least onedouble bond in its ring. Detailed examples of the C₂-C₁₀heterocycloalkenyl group are a 2,3-hydrofuranyl group and a2,3-hydrothiophenyl group. A C₂-C₁₀ heterocycloalkenylene group usedherein refers to a divalent group having the same structure as theC₂-C₁₀ heterocycloalkenyl group.

A C₆-C₆₀ aryl group used herein refers to a monovalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms, and a C₆-C₆₀arylene group used herein refers to a divalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms. Detailedexamples of the C₆-C₆₀ aryl group are a phenyl group, a naphthyl group,an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and achrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene groupeach include two or more rings, the rings may be fused to each other.

A C₂-C₆₀ heteroaryl group used herein refers to a monovalent grouphaving a carboncyclic aromatic system that has at least one hetero atomselected from N, O, P, and S as a ring-forming atom, and 2 to 60 carbonatoms. A C₂-C₆₀ heteroarylene group used herein refers to a divalentgroup having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, P, and S as a ring-forming atom, and 2 to 60carbon atoms. Examples of the C₂-C₆₀ heteroaryl group are a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, and an isoquinolinyl group. Whenthe C₂-C₆₀ heteroaryl group and the C₂-C₆₀ heteroarylene group eachinclude two or more rings, the rings may be fused to each other.

A C₆-C₆₀ aryloxy group used herein indicates —OA₁₀₂ (wherein A₁₀₂ is theC₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group indicates —SA₁₀₃(wherein A₁₀₃ is the C₆-C₆₀ aryl group).

A monovalent non-aromatic condensed polycyclic group used herein refersto a monovalent group (for example, having 8 to 60 carbon atoms) thathas two or more rings condensed to each other, only carbon atoms as aring forming atom, and non-aromacity in the entire molecular structure.A detailed example of the monovalent non-aromatic condensed polycyclicgroup is a fluorenyl group. A divalent non-aromatic condensed polycyclicgroup used herein refers to a divalent group having the same structureas the monovalent non-aromatic condensed polycyclic group.

A monovalent non-aromatic condensed heteropolycyclic group used hereinrefers to a monovalent group (for example, having 2 to 60 carbon atoms)that has two or more rings condensed to each other, has a heteroatomselected from N, O P, and S, other than carbon atoms, as a ring formingatom, and has non-aromacity in the entire molecular structure. Anexample of the monovalent non-aromatic condensed heteropolycyclic groupis a carbazolyl group. A divalent non-aromatic condensedheteropolycyclic group used herein refers to a divalent group having thesame structure as the monovalent non-aromatic condensed heteropolycyclicgroup.

In the present specification, at least one substituent selected from thesubstituted C₃-C₁₀ cycloalkylene group, the substituted C₂-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group,the substituted C₂-C₁₀ heterocycloalkenylene group, the substitutedC₆-C₆₀ arylene group, the substituted C₂-C₆₀ heteroarylene group, thesubstituted divalent non-aromatic condensed polycyclic group, thesubstituted divalent non-aromatic condensed heteropolycyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), and—B(Q₁₆)(Q₁₇);

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅) and—B(Q₂₆)(Q₂₇); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), and —B(Q₃₆)(Q₃₇),

Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ to Q₃₇ may be eachindependently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid or a saltthereof, a sulfonic acid or a salt thereof, a phosphoric acid or a saltthereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₂-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, and amonovalent non-aromatic condensed heteropolycyclic group.

For example, at least one substituent selected from the substitutedC₃-C₁₀ cycloalkylene group, the substituted C₂-C₁₀ heterocycloalkylenegroup, the substituted C₃-C₁₀ cycloalkenylene group, the substitutedC₂-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylenegroup, the substituted C₂-C₆₀ heteroarylene group, the substituteddivalent non-aromatic condensed polycyclic group, the substituteddivalent non-aromatic condensed heteropolycyclic group, the substitutedC₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, thesubstituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group,the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a cyclopentylgroup, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a pentalenyl group, an indenylgroup, a naphthyl group, an azulenyl group, a heptalenyl group, anindacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group,a phenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a naphthacenyl group, a picenyl group, a perylenyl group, apentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenylgroup, a coronenyl group, an ovalenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, an imidazolyl group, a pyrazolylgroup, a thiazolyl group, an isothiazolyl group, an oxazolyl group, anisooxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a furinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzooxazolyl group, an isobenzooxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a thiadiazolyl group, animidazopyridinyl group, an imidazopyrimidinyl group, —N(Q₁₁)(Q₁₂),—Si(Q₁₃)(Q₁₄)(Q₁₅), and —B(Q₁₆)(Q₁₇);

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenylgroup, an indenyl group, a naphthyl group, an azulenyl group, aheptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenylgroup, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group,an imidazopyridinyl group, and an imidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenylgroup, an indenyl group, a naphthyl group, an azulenyl group, aheptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenylgroup, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group,an imidazopyridinyl group, and an imidazopyrimidinyl group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a pentalenyl group, an indenylgroup, a naphthyl group, an azulenyl group, a heptalenyl group, anindacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group,a phenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a naphthacenyl group, a picenyl group, a perylenyl group, apentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenylgroup, a coronenyl group, an ovalenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, an imidazolyl group, a pyrazolylgroup, a thiazolyl group, an isothiazolyl group, an oxazolyl group, anisooxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a furinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinylgroup, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzooxazolyl group, an isobenzooxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a thiadiazolyl group, animidazopyridinyl group, an imidazopyrimidinyl group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), and —B(Q₂₆)(Q₂₇); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), and —B(Q₃₆)(Q₃₇),

Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ to Q₃₇ may be eachindependently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid or a saltthereof, a sulfonic acid or a salt thereof, a phosphoric acid or a saltthereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenylgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a naphthacenyl group, apicenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a rubicenyl group, a coronenyl group, anovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group,an imidazolyl group, a pyrazolyl group, a thiazolyl group, anisothiazolyl group, an oxazolyl group, an isooxazolyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, anisoindolyl group, an indolyl group, an indazolyl group, a furinyl group,a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzoimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzooxazolylgroup, an isobenzooxazolyl group, a triazolyl group, a tetrazolyl group,an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a thiadiazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group.

The following Example and Comparative Example are provided in order tohighlight characteristics of one or more embodiments, but it will beunderstood that the Example and Comparative Example are not to beconstrued as limiting the scope of the embodiments, nor is theComparative Example to be construed as being outside the scope of theembodiments. Further, it will be understood that the embodiments are notlimited to the particular details described in the Example andComparative Example.

Example 1 (Insertion of RbI Hole Injection Layer)

An ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm and then,sequentially sonicated in acetone, isopropyl alcohol, and pure water,each for 15 minutes, and then, cleaned using UV ozone for 30 minutes.

Next, RbI was vacuum deposited on the ITO glass substrate to form a holeinjection layer having a thickness of 5 Å.

TCTA was vacuum deposited on the layer to form a hole transport layerhaving a thickness of 600 Å.

Then, H1 as a host and 5% of Ir(pq)2acac (300 Å) are vacuum deposited onthe hole transport layer to form an emission layer having a thickness of300 Å.

Next, Alq3 was vacuum deposited on the emission layer to form anelectron transport layer having a thickness of 300 Å. 10 Å of LiF(electron injection layer) and 2000 Å of Al (cathode) were sequentiallyvacuum deposited on the electron transport layer, and an organiclight-emitting device was manufactured.

Comparative Example 1 (Reference)

An organic light-emitting device was manufactured in the same manner asin Example 1, except that a RbI hole injection layer was not formed.

Comparison of Example and Comparative Example

The characteristics of the organic light-emitting device manufactured inExample according to an embodiment was compared to that of the organiclight-emitting device in Comparative Example, and the results thereofare shown in Table 1 below.

TABLE 1 Driving Voltage (V) Efficiency (cd/A) Example 1 4.6 9.2Comparative Example 1 4.6 8.3

Referring to Table 1, the organic light-emitting device of Example 1 hasbetter characteristics, e.g., efficiency, compared to the organiclight-emitting device of Comparative Example 1.

FIG. 4 illustrates a graph of an efficiency of each of the devices ofExample 1 and Comparative Example 1. FIG. 4 also shows that the organiclight-emitting device of Example 1 has better characteristics, e.g.,efficiency, compared to the organic light-emitting device of ComparativeExample 1.

By way of summation and review, an organic light-emitting device mayinclude a first electrode disposed on a substrate, and a hole transportregion, an emission layer, an electron transport region, and a secondelectrode, which may be sequentially disposed on the first electrode.Holes provided from the first electrode may move toward the emissionlayer through the hole transport region, and electrons provided from thesecond electrode may move toward the emission layer through the electrontransport region. Carriers, such as holes and electrons, may berecombined in the emission layer to produce excitons, which may changefrom an excited state to a ground state, and light may be generated.

One or more exemplary embodiments include an organic light-emittingdevice that may have improved electric characteristics, e.g., providedby reducing an energy barrier between an electrode and an organic layer,and improving an interface characteristic of the organic layer.

As described above, according to the one or more of the above exemplaryembodiments, the efficiency of an organic light-emitting deviceaccording to exemplary embodiment may be improved.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. An organic light-emitting device, comprising: afirst electrode; a second electrode facing the first electrode; and anorganic layer between the first electrode and the second electrode andincluding an emission layer, the organic layer including a holeinjection layer that is in direct contact with the first electrode andconsists of a metal compound having a work function in a range of morethan 0 eV to 3 eV.
 2. The organic light-emitting device as claimed inclaim 1, wherein the metal compound includes a halide of an alkalimetal.
 3. The organic light-emitting device as claimed in claim 1,wherein the metal compound includes a halide of an alkaline earth metal.4. The organic light-emitting device as claimed in claim 1, wherein themetal compound includes a halide of a lanthanide metal.
 5. The organiclight-emitting device as claimed in claim 1, wherein the metal compoundincludes a halide of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Yb, or Sm.6. The organic light-emitting device as claimed in claim 1, wherein themetal compound includes LiF, NaF, KF, RbF, CsF, BeF₂, MgF₂, CaF₂, SrF₂,BaF₂, YbF, YbF₂, YbF₃, or SmF₃.
 7. The organic light-emitting device asclaimed in claim 1, wherein the metal compound is in a layer having athickness of 1 Å to 30 Å.
 8. The organic light-emitting device asclaimed in claim 1, wherein the metal compound is in a layer thatconsists of the metal compound and a hole injection material.
 9. Theorganic light-emitting device as claimed in claim 8, wherein the metalcompound is in a layer having a thickness of 1 Å to 100 Å.
 10. Anorganic light-emitting device, comprising: a first electrode; a secondelectrode facing the first electrode; and an organic layer between thefirst electrode and the second electrode and including an emissionlayer, the organic layer including an electron injection layer and ahole injection layer, the hole injection layer including a metalcompound, the metal compound having a work function in a range of morethan 0 eV to 3 eV and including a halide of a lanthanide metal, wherein:the first electrode is an anode, the second electrode is a cathode, andthe organic layer includes: a hole transport region between the firstelectrode and the emission layer, the hole transport region includingthe hole injection layer and optionally one or more of a hole transportlayer or an electron blocking layer, and an electron transport regionbetween the emission layer and the second electrode, the electrontransport region including the electron injection layer, and optionallyone or more of a hole blocking layer or an electron transport layer, andthe hole injection layer including the metal compound directly contactsthe anode.
 11. The organic light-emitting device as claimed in claim 10,wherein the hole injection layer consists of the metal compound.
 12. Theorganic light-emitting device as claimed in claim 10, wherein the holeinjection layer consists of the metal compound and a hole injectionmaterial.
 13. An organic light-emitting device, comprising: an anode; acathode facing the anode; and an organic layer between the anode and thecathode and including an emission layer, the organic layer including: ahole transport region between the anode and the emission layer, the holetransport region including a hole injection layer, and an electrontransport region between the emission layer and the cathode, theelectron transport region including an electron injection layer,wherein: the hole injection layer includes LiCl, NaCl, KCl, RbCl, CsCl,BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, YbCl, YbCl₂, YbCl₃, SmCl₃, LiBr,NaBr, KBr, RbBr, CsBr, BeBr₂, MgBr₂, CaBr₂, SrBr₂, BaBr₂, YbBr, YbBr₂,YbBr₃, SmBr₃, LiI, NaI, KI, RbI, CsI, BeI₂, MgI₂, CaI₂, SrI₂, BaI₂, YbI,YbI₂, YbI₃, or SmI₃, and the hole injection layer directly contacts theanode.
 14. The organic light-emitting device as claimed in claim 13,wherein the hole injection layer includes NaBr, KBr, RbBr, CsBr, BeBr₂,SrBr₂, or BaBr₂.
 15. The organic light-emitting device as claimed inclaim 13, wherein the hole injection layer includes NaI, KI, RbI, CsI,BeI₂, SrI₂, or BaI₂.
 16. The organic light-emitting device as claimed inclaim 13, wherein the hole injection layer includes: NaI, RbI, BeI₂,SrI₂, or BaI₂.
 17. A display apparatus, comprising an organiclight-emitting device, wherein the organic light-emitting deviceincludes: a first electrode; a second electrode facing the firstelectrode; and an organic layer between the first electrode and thesecond electrode and including an emission layer, the organic layerincluding an electron injection layer and a hole injection layer, thehole injection layer including a metal compound, the metal compoundhaving a work function in a range of more than 0 eV to 3 eV andincluding a halide of a lanthanide metal, wherein: the first electrodeis an anode, the second electrode is a cathode, and the organic layerincludes: a hole transport region between the first electrode and theemission layer, the hole transport region including the hole injectionlayer and optionally one or more of a hole transport layer or anelectron blocking layer, and an electron transport region between theemission layer and the second electrode, the electron transport regionincluding the electron injection layer, and optionally one or more of ahole blocking layer or an electron transport layer, and the holeinjection layer including the metal compound directly contacts theanode, wherein the first electrode of the organic light-emitting deviceis electrically connected to a source or drain electrode of a thin filmtransistor.